code: def assertLen(self, iterable, expected_len, msg=None):
      self.assertEqual(len(iterable), expected_len, msg=msg)
  
imports: import json
  import shutil
  import tempfile
  import unittest
  import numpy
  import tree
  from keras import backend
  from keras import ops
  from keras import utils
  from keras.backend.common import is_float_dtype
  from keras.backend.common import standardize_dtype
  from keras.backend.common.global_state import clear_session
  from keras.backend.common.keras_tensor import KerasTensor
  from keras.models import Model
  from keras.utils import traceback_utils
label_desc: Use image node_id 8 for calling the TestCase obj's underlying member method code with example usage: obj.assertLen(iterable, expected_len, msg) without return types